1. Field of the Invention
The present invention relates generally to a caption display apparatus and method thereof. More specifically, the present invention relates to an apparatus and method for displaying a different caption service menu depending on a type of a caption service input from a digital receiver.
2. Description of the Related Art
Recently, most broadcast content provided to TVs include a caption. There are two classes of captions: an open caption and a closed caption. An open caption is a subtitle and is displayed on a TV screen upon transmission from a broadcast station, and the viewer does not have the option of turning-off an open caption. A closed caption is a hidden caption and is displayed on a TV screen only when the TV has a caption receive function. For example, an open caption is an onscreen description of information such as staff profile, song title, singer, Civil Defense training notice, and Korean subtitle for rental videos, which is displayed to the viewer regardless of the viewer's intention. On the other hand, a closed caption is available to a viewer who wants to obtain dialogue or additional information associated with a program. Especially, the closed captioning function can display dialogue of a television program or subtitles of a video on the screen to aid a language study or hearing-impaired people.
Caption broadcasting has conformed to a TV broadcast transmission of the National Television Standards Committee (NTSC) but various transmission systems have been adopted with the advent of digital TVs.
The caption services are provided through diverse transmission media such as terrestrial broadcasting or cable satellites, and the provided caption services are different from each other. While the Electronic Industries Association (EIA) 608 caption has been provided only to NTSC TVs, the digital broadcasting also transmits the EIA 608 caption. Accordingly, it is required to separate a caption service menu for each channel.
Caption data for a digital TV is contained and delivered in a user data region of a bit stream.
The user data region consists of a channel carrying NTSC caption data in line 21 of an NTSC signal or Digital Television Closed-Captioning (DTVCC) caption data. The NTSC caption data conforms to the EIA 608 standard, and the DTVCC caption data conforms to the EIA 708 standard.
The EIA 708 caption service alone is not always input as an input data stream of a digital caption data processing system in a specific broadcast, but the EIA 608 caption service may be provided. For example, in cable and satellite digital broadcasting, only the EIA 708 caption data can be input, or both the EIA 708 caption data CC1, CC2, . . . , Service 1, Service 2, . . . and the EIA 608 caption data CC1, CC2, CC2 and CC4 can be input together.
In the above situation, the digital caption service system displays an EIA 708 caption service menu as shown in FIG. 2A when a user selects the caption service menu.
Since the digital caption data processing system displays the caption service menu relating to the EIA 708 in FIG. 2A without regard to whether the input caption is the EIA 708 caption or the EIA 608 caption, the user cannot correctly learn which caption service is provided.
In view of the related art, a need arises to display a caption service menu discriminated for a user's convenience even when the EIA 708 caption or the EIA 608 is input.